Gun control system



Aug. 27, 1946. A. P. DAVIS GUN CONTROL SYSTEM Filed sept. 6. 1935 A. P..DAVIS GUN CONTROL SYSTEM Aug.. V27, 1946.

Filed Sept. 6,. 1933 2 Sheets-Sheet 2 vENroR ATTORNEYS Patented Aug. 27,4 1946 GUN CONTROL SYSTEM Arthur Pattison Davis, New York, N. Y., assignor to Arma Corporation, a corporation of New York Application September 6, 1933, Serial No. 688,285

(Cl. 89--41'l 9 Claims. l

This invention relates to systems for the control of the positions and movements of gun mounts and the like to follow the movements of a primary element such as a sighting device or gun director.

The main object of the invention is to provide a combined automatic and manual control involving simple control circuits and providing accurate and efcient means for moving the gun mount or other secondary element.

Further objects of the invention particularly in the reduction of the reaction on the hand wheels of the manual control and the very critical precision of the gun mount moving will appear from the following specication taken in connection with the accompanying drawings in which Fig. 1 is a diagram of a control system illustrating one embodiment of this invention;

Fig. 2 is a vertical section view of one of the devices employed in said system,

Fig. 3 is a plan view of the device shown in Fig. 2,

Fig. 4 is a plan view in outline of a modified detail, and

Fig. 5 is an elevational view with parts in section of the apparatus shown in Fig. 4.

In the specic embodiment shown in the drawings, the system is illustrated in connection with a gun director D and a gun mount M. Electrical means are provided for controlling the movements of the gun mount M to follow very precisely the movements of the gun director D, said means comprising transmitters of the self-synchronous type at the director, low speed transmitter 6 being connected to drive the low speed synchronizing motor l. at the gun mount and a high speed transmitter 8 being connected tc drive the high speed motor 9.

An alternative hand operation is provided by connecting the hand wheels IU to gears II, I2, I3 and clutch l and gears I5 to one side of the differential iii, the other side of the differential I6 being geared at II and I8 to the gun mount table gear I9. The hand drive is geared to the differential by gears I5 on one side of the differential gear 2| while the high speed motor 9 of the automatic control has its gear 29 meshed with the other side of gear 2l. When the automatic drive is in operation the Clutch I4 of the magnetic type is released and when the drive is shifted to hand operation the clutch I4 is engaged to complete the train of gearing from the hand Wheels lll through to the gun mount table gear I9.

Taking rst the hand operating means, the hand wheels I0 being connected to one side of the differential I6 and the gun mount I 9 to the other side, the output of the differential I6 is proportional to the angular difference between gun mount i9 and hand wheels I0 and the speed of the output shaft 22 of differential I 6 is proportional to the difference in speed between the gun mount I9 and hand wheels I0.

This output shaft 22 of differential I6 is geared at 23, 24 to one side of differential 25 and through this diiferential and its output shaft 26 to the control box of the oil gear 2l. The output of differential I6 is thus transmitted to control shaft 28 of the oil gear but with a modification at the diiferential 25 which, as is later explained in detail, subtracts from the angularity of shaft 22 an angle proportional to the differential speed of the gun mount I9 and hand Wheels I9 at each instant.

The input or A end of the auxiliary oil gear 2l is driven at substantially constant speed by the power motor 28 and the speed of the B or output end is proportional to the deflection of the control shaft 26. is connected by gearing 29, 39 to the control shaft SI for the tilting box of the main oil gear 4! (of the variable speed type) having its A end driven by motor 28 and its B end connected by gears 32, 33, 34 and 35 to drive the gun mount gear I9. The speed of the B end of main oil gear 40 is proportional to the deflection of control shaft 3I. It follows that the acceleration of the B endV of gear 4G is proportional to the speed of the control shaft 3| and therefore also proportional to the deflection of the control shaft 26 of the auxiliary gear 2l. Since the B end of gear 40 is geared to the gun mount gear I9 and since torque is proportional to acceleration it follows that the torque applied to gun mount gear I9 is proportional to the deviation of the gun mount from the position of the hand wheels I0 minus a factor f interposed between shafts 22 and 26 and regulated to be proportional to the differential velocity of the gun mount gear I9.

By properly proportioning this factor f the system can be critically damped to avoid hunting while at the same time reducing to a minimum the instantaneous deviation of the gun mount M from thev director D. For example, if a is taken as equal to the instantaneous deviation of the gun mount M from the director, it is also proportional to the output of dilerential I 6. The factor f thus is proportional to the diierential speed of gun mount gear I9 and is added algebraically to a between shafts 22? and 26 by differential 25 and its associated anti-hunt device 36.

The deflection of control shaft 26 of oil gear 21 is proportional to this algebraic sum The output of oil gear 27 piston 49. Oil will flow from one cylinder to the other over the circuit indicated by the arrows. The piston 49 will move in the direction of reduced pressure until the restraining forces of the Vsprings 55 balance the forces of pressure difference. For any given velocity of the shaft 31 the piston 49 will assume a definite position either to the left or right of center, depending upon the diwhere k1 and k2 are constants of proportionality.

Now the speed of the B end of gear 49 is proportional to the deflection s of control shaft 3|. Therefore since the gun mount is driven from this B end the differential speed der dt of mount M is proportional to deflection s, so

orv

rank-e dif 3dr where k3 is a constant of proportionality.

Now substituting in (l) we have Equation a, is of well known type characteristic of a system with inertia, restoring torque proportional to displacement from a stable position and damping proportional to velocity. By making K 121=4K2 the damping is made critical so that while the gun mount M follows director D with almost no deviation it does not overrun or hunt.

The mechanism contributing the anti-hunt factor f is indicated at 36 Fig. 1 and shown more in detail in Figs. 2 and 3. Itcomprises a gear pump 44 having its driving shaft 31 provided with gear 38 meshing with gear 24 driven by gear 23 on shaft 22. The output of the gear pump 44 is transformed into rotary motion by pressure developing means, which rotary motion turns shaft 4| carrying gear 42 meshing with gear 43 of the other side of differential 25.V The shaft 22 thus drives one side of differential 25 while the other side is driven from the anti-hunt device 35, the output of diierential 25 beingthe algebraic sum of these inputs. To develop the input factor f the anti-hunt device has its gear pump 44 driven by shaft 31 (Figs. 2 and 3) to develop oil pressure between the passages 45, 49 in either direction depending on the direction of rotation of the gears. Passages 45, 46 are connected to opposite ends of cylinders 41, 48 respectively andY so develop pressure against one end or the other of double ended piston 49, normally centered by springs 59. The piston rod carries rack teeth engaging pinion 5,2- onjoutput shaft 4| passing through stuffing box 53 and carrying gear 42 at its outer end. The piston ends are provided with passages 55 which permit a restrictedv flow of oil from one cylinder to the other.V

Operation is as follows: Rotation of the input shaft 31 will actuate the gear pump 44 and unbalance the oil pressure on the two ends of the rection of rotation of the shaft. A change in velocity of the shaft 31 will alter the balance between the forces of pressure and the force of the springs and cause the piston to move to a new position of equilibrium.

The motion of the piston 49 is converted into angular motion at the shaft 4| by the rack and gear. Since angular motion of the shaft 4| depends upon motion of the piston 49, which in turn depends upon a change in pressure difference between the piston ends and since this pressure difference is a function of the velocity of the input shaft 31, the angular position of the shaft 4| is a function of the velocity of the shaft 31 and the Velocity of the shaft 4| is a function of the rate of change of velocity of the shaft 31.

The characteristics of the anti-hunt device are so arranged as to make the constants of proportionality in each direction such that K12=4K2 as above explained, and thus attain a critical damping in each direction.

The system istherefore dead beat in operation while at the same timeproviding through motor 28 and hydraulic gear 49 the power for moving the gun mount M. All the operator has to do is to turn the hand wheels I9 as determined by his information and the gun mount will precisely follow. While relatively large powers are available from the drive there is little resistance at the control. The hand power is only required to turn the parts through differentials I6 and 25 to turn the control shaft of the light auxiliary gear 21. Very little effort is requiredby the operator to accurately control the power delivered to the gun mount.

Similarly when the automatic Vdrive through high speed motor 9 is substituted for the hand operation the oil gear 40 provides the power and the anti-hunt device 3B gives the-desired damping and close control. AFor this automatic gun control the magnetic clutch |4 is energized to disconnect the hand wheelsll) and the high speed motor 9 is connected to the high speed transmitter 8 by three wire cable 69 from the transmitter to contacts 8| of synchronizing relay 62, then through wires 63 and connections 64 to three wire cable 65 to contacts B6 of limit relay 61 and through three wire cable- 68 to motor 9.

Any motion ofthe director D will therefore be imparted at a high angular speed to the motor Y1| at the low speed synchronizing motor 1, frame 12 of which is geared to turn with the gun mount as shown. At the extremes of movement ofthe mount lug 13 on frame 12 engages one or the other 0f contacts 19, 1| to close it and correr spondingly energize the limit relays 61, 11, and disconnect the low and high speed motors 1, 9 from the transmitters 6, 8.and at the same time deenergizing the clutch I4, thus permitting itto connect the hand-wheels I Il to one side of .differential I6 to resume manual control and bring the gun mount to rest. Energizing relay 6l opens contacts 66 of the high speed motor 9 and contacts i6 of the low speed motor and energizing relay 17 opens contacts 'IS of the circuit for the magnetic clutch Id. Conversely when the mount moves so that both limit switches lli, 'il are open the limit relays 6i, il will close to restore the automatic control.

To provide `for synchronizing the gun mount for va vlarge initial deviation between the director and the mount, the low speed motor whose frame is geared to the mount is connected electrically to the low speed transmitter S; Three wireable Sii leads to contacts "F6 of limit relay 81, then to three wire cable 8| to the motor l. The rotor 82 of motor 'l carries contact arm 83 which for deviation of the gun mount more than a predeterlmined amount from the direction will make contact with one or the other of stationary contact segments 84, 85. This contact energizes the synchronizing relay 52 and one or the other of synchronizing relays 85, 31, breaking contacts iii and making contacts 58 or 89. If contact is made with segment 84 contacts 88 are closed to connect the high speed synchronizing transmitter (iii to high speed motor in such manner as to cause the motor 5 to lead or lag by 66 whichever direction will impose a torque on the gun mount in a direction to reduce the deviation. Transn mitter Si] is then connected by three wire cable 9i and contacts 88 to wires 53, contacts 5d, three wire cable F55, limit contact 66 and three wire cable t1 to motor 9. tion for the connection made by segment 33,'there will then be an effective lead of the high speed control ahead of the gun mount and rotation of the mount in the direction to catch up with the director and until the mount and director are sufficiently nearly in agreement to move contact 83 from segment d4 when the control from transmitter 8 is restored. Similarly 0n contact oi arm S3 with segment 85, connection will be correspondingly made through contacts 89 which shift l the phase relation so that motor 9 will lag for leading arrangement with contacts 83 or lead for lagging arrangement with said contacts 88. Assuming a 60 lag between the rotor circuits of transmitter 9@ and motor e, that is, with the phases of the rotor of transmitter 9i) in a direction opposite to the relation when contact 83 engages segment dit, this gives rotation oi the gun mount in the opposite direction, which rotation will continue until contact at 83 is opened.

The constant catch up torque thus imposed on gun mount M rapidly reduces the deviation to cause arm 33 to leave the segment 84 or 85 so that when the gun mount arrives within a predetermined defiection from the angular position of the director, relays t2 and B6 or 81 are deenergized, the high speed motor is disconnected from the high speed transmitter Sii and reconnected to the director transmitter 8.

The transmitters E and Bil and motors 'l and 9 are of the self-synchronous type having their fields and armatures relatively rotatable, the three-phase armatures being interconnected'as above described and the fields 93, 911,95, 9% and Sl supplied from a source of alternating current 'ifi byiconnecting conductors not shown. In this apparatus any convenient arrangement of parts and relative rotations may be used. In the embodiment shown, field coils 93, 94 of transmitters 6, 8 rotate with the gears 93', 9d meshing 'with Assuming a leading rela- 6 the director gear lili). Armature 82 of motor l is rotatably carried by the frame l2 and carries the contact arm 82. Armature IBI of the transmitter 90 rotates with gear 02 driven by the gun mount gear I9, and armature 103 of motor 9 rotates with the gear 20.

The A. C. supply 'I4 also furnishes the current for magnetic clutch I4, two wire cables 96 connecting the leads 14 to relay contacts I8 and thence to the clutch. The solenoid currents `for the synchronizing and limit relays are also in circuit with the supply '14, conductor 91, connecting relays 'il and 6T in series with limit contacts ie, 1I (in parallel with each other) to return conductor 98. The synchronizing relays are supplied by conductor 99 connected to have relay 62 in series with parallel circuits through relay 81S and segment 34 on one side and relay Bland segment on the other, thence through .contact arm 83 to return wire 98.

The parts between output `'shaft 22 of differential i6 and control shaft 3l of main oil `gear 40 may be replaced by a modified form of liritermediate control means as shown for instance in Figs. 4 and 5. The power motor 2B drives the A end of the main hydraulic gear i9 as shown in Figs. 1 4 and 5 and the control shaft 3i of said gear is geared through the gear ESS meshing with the gear lill of the differential H33. Gear H31 turns with sleeve H39 carrying pinion Hi! meshing with the rack -Hl between work pistons H2, H3 in cylinders Hd and H5, the ports H6, Il? of which are controlled by piston valves H8, H9 connected by rack rod E2G. Pistons H8, H9 slide in cylinder 132i having open ends l23, i2!! communicating directly Iwith the oil in the oil reservoir tank 25 in which the apparatus is located. Between pistonsV HS, H9 oil pressure is maintained through inlet l2@ and piping i2? from the oil pressure pump 29 driven by pulleys and belting |28 from the shaft of .niotOr 23.

Balanced pressures are thus `maintained on both sides of each of these piston valves H8, H9 and in their normal central position they cover and close ports Al i6; H1 to hold the pistons i i2, H3 in set position. Piston valves H3, H9 are driven by pinion i3@ on shaft ISS connected to the differential spider I32 carrying the ,bevel gears l3i meshing with bevel gears Hifi and |22'. The bevel gear 22 is rigid with an upper bevel gear |22 meshing with gear Vii connected to rotate with the outputshaft 22 of the differential l5. Y

The A end of this auxiliary control is thus geared to the output of the differential i5, the B end being geared directly to con-trol shaft 3l of the main hydraulic gear lit. For the operation of this auxiliary gear the oil pump 29 maintains oil at a predetermined pressure. The A end of the auxiliary gear is moved to an .angle proportional to the deviation of the director D and the mount M. This offsets the valve pistons H8, H9, say to the right, uncovering the ports H6, H7 and connecting port HB to the low pressure reservoir and port H'l to the high pres- Isure supply between valves H8, H9. The pressure on pistons H2, H3 are thus unbalanced, and these pistons move to 'the left turning pinion llil and gear lill and control shaft Si of the main oil gear 4i) to drive the B end thereof in a direction to reduce the deviation between mount'M and director D. 'Bevel gear l'l thus forms one side of the differential |58 and its movement-through gears .491', .31 .and E22 .turns y7 the shaft |33 to bring the valve pistons H8, H9 back to the neutral position covering and Closing the DOIts H6, Ill so as to bring the work pistons H2, H3 to rest. o From this it follows that the motion of the B end is proportional to the motion of the A end with greatly increased torque available, the torque required to actuate the A end being very small in comparison to the available output torque. Y Y

The system of this invention thu's combines the automatic and manual control so as to impose a minimum resistance on the initiating control members of each, while at'the-same time applying a multiplied and adequate force to accurately turn the gun mount. The apparatus involved is simple, avoiding electrical complications and depending in the main upon mechanical apparatus of established performance.

I claim:

1. In a control system for reproducing motion the combination with a gun mount of a director element, a motor means for supplying power to move said mount, control means for regulating said power, operating means for said control means comprising a synchronizing transmitter moving with said gun mount and actuating said control means to impart a relatively rapid movement to the gun mount under predetermined conditions, and a motor moving in synchronism with the director and actuating said control means to rmaintain said gun mount in substantial corretermined conditions.

2. In a control system for reproducing motion the combination with a gun mount of a director element, a motor means for supplying power to move said mount, control means for regulating said power, operating means for said control means comprising a synchronizing transmitter moving with said gun mount and actuating said control means to impart a relatively rapid movement to the gun mount under predetermined conditions, a motor moving in synchronism with the director andv actuating said control means to maintain said gun mount in substantial correspondence with said director under other predetermined conditions, and means for automatically rendering the lsynchronizing transmitter or the motor operative in accordance with the said predetermined conditions. Y

3. In a control system rfor reproducing motion the combination with a director element and a follower, of a source of power for the drive of said follower and Ymeans for controlling Ysaid powver comprising differential means for comparing the relative Speeds of the director and follower and moving a control member at a speed proportional to the difference in said speeds, differential means for modifying the motion of said member by a predtermined variable directly proportional to the difference in said speeds, and mechanical means for applying said modified motion to control the torque applied to said follower by said drive.

4. In a control system for reproducing motion the combination with a director element and a follower, of a source of power for the drive of said follower and means for controlling said power comprising dilerential means for comparing the relative speeds of the director and follower and moving a control member at a speed proportional to the difference in said speeds, differential means for modifying the motion .of said member by a predetermined variabledirectly proportional to the difference in said speeds, and mechanical means for applying said modified motion to control the torque applied to said follower by said drive, said mechanical means including speed varying means between said power source and said follower.

5. In a control system for reproducing motion the combination with a director element and a follower, of a source of power to drive said follower and means for controlling said power comprising means for comparing the relative speeds of the director and follower and moving a member at a speed proportional to the difference in said speeds, means for modifying the motion of said member by a predetermined variable proportional to the differenceA in said speeds, mechanical means for applying said modified motion to control the Ytorque applied to said follower by said drive, said mechanical means including speed varying means between said power source and said follower, and a second speed varying means for regulating said first named speed varying means.

6. In a control system for reproducing motion the combination with a director element and a follower, of a source of power to drive said follower and means for controlling said power comprising means for comparing the relative speeds of the director and follower and moving a member at a speed proportional to the difference in said speeds, means for modifying the motion of said member by a predetermined variable proportional to the difference in said speeds, mechanical means for applying said modified motion to control the torque applied to said follower by said drive, said mechanical means including speed varying means 'between said power source and said follower, and a second speed varying means driven from said power source and acting to regulate said first named speed varying means.

7. In a gun control system the combination with a gun mount and a director element, a driver for the gun mount, differential mechanism driven on one side in correspondence with said director elementrand kone the other side in correspondence with saidgun mount, and control means actuated by said diierential mechanism and connected to said driver, to vary the torque thereof to be proportional to the angular devia-Y tion between the gun mount and the director element, said control means having between said differential and said driver a second differential device subtracting from said control a corrective factor directly proportional to the differential speed of the gun mount and director element.

8. In a gun control system the combination with a gun mount and a director element, a driver for the gun mount, differential mechanism driven on one side in correspondence with said director element and on the other side in correspondence with said gun mount, and control means Vactuated by said differential mechanism and connected to said driver to vary the torque thereof to be proportional to the angular deviation between the gun mount and the director element, said control means having between said differential and said driver a second differential device subtracting from said control a corrective factor directly proportional to the differential speed of the gun mount and comprising a connection to said first mentioned differential, an anti-hunt device driven thereby Vand connected to drive the other side of said differential and a differential output connected to said driver for the gun mount.

9. In a control system for reproducing motion, the combination with a director and a follower, of a drive for said follower, control means therefor, and operating means for said control means, comprising means responsive to a deviation between the director and follower within a predetermined range for actuating the drive, and

10 means responsive to a deviation between the director and follower in excess of said predetermined range for controlling said control means in accordance with a predetermined articial deviation independent of the actual deviation for moving the follower into said range.

ARTHUR PATTISON DAVIS. 

